You are not legally allowed to keep or drive a vehicle on a public highway without a valid tax disc.
If you are exporting the vehicle permanently and you are doing this from S'oton then I'd put it on a trailer and get a road-legal vehicle to take it.
An MOT is not enough, you will need tax, MOT, insurance to drive the car legally anywhere. If you do not have any one of these elements, then any insurance is likely to be invalid.
DON't DO IT!